When manufacturing low-wattage high-pressure discharge lamps on a lamp-making machine, the ionizable filling must be introduced into the discharge vessel with particular care. Because low-wattage high-pressure discharge lamps have relatively small discharge volumes and correspondingly small metered amounts of filing components, even slight contamination of the discharge volume can affect the light output of the lamp or can even cause the lamp to fail. Thus, flushing and filling processes carried out with a conventional pump stand of the type used for other gas discharge lamps, entail considerable risks.
The production of sodium high-pressure discharge lamps is typically carried out for the most part inside a glove box in a protective gas atmosphere. For processing, precursor products or subassemblies, the sodium high-pressure discharge lamps themselves are fed in batches to the interior of the glove box through one or more gates. Tools are located in the interior of the glove box for processing and/or working on the lamps and/or the lamp precursor products. These tools or the work-stations are interrelated by a transport system for the lamps and/or lamp precursor products. They are highly automated in order to provide high output.
This technology, however, cannot readily be adapted to the manufacture of other high-pressure discharge lamps, such as mercury vapor high-pressure discharge lamps or halogen metal vapor high-pressure discharge lamps, since some of the production steps required for these lamps, such as sealing off the ends of the discharge vessels and freezing out the noble gas filling component, can be accomplished in a glove box only at very high and hardly acceptable technological effort and expense.
Moreover, the high degree of automation of the procedures within the glove box may lead to a slight contamination from dust, abrasion, and lubricant vapors, which contamination can no longer be tolerated in the manufacture of discharge lamps having extremely small discharge volumes down to 0.03 cm.sup.3 and correspondingly small amounts of metered filling components. Such lamps are used, for example, as low-wattage high-pressure discharge lamps in motor vehicle headlights. On the other hand, if a high throughput capacity is to be attained, it is impossible to dispense with the high degree of automation of the procedures even in the manufacture of low-wattage high-pressure discharge lamps.